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Learn about microbial fuel cells that generate electricity with bacteria

 In the search for alternative, renewable, and environmentally friendly energy sources, researchers have found a way to take advantage of bacteria to generate energy through microbial fuel cells.

Learn about microbial fuel cells that generate electricity with bacteria

Generate electricity with bacteria

The search continues for alternative and renewable energy sources, to exclude fossil fuels and natural gas, and not rely on them to generate electricity. In order to find an alternative, the world is turning towards natural and renewable sources of energy, and one of the most important of these sources is "biomass". Today, energy can be obtained from biomass in several ways, including the microbial fuel cell.

What is a microbial fuel cell (MFC)?

Microbial fuel cells are biofuel cells that use bacteria or microorganisms to convert organic matter into electrical energy.

Microorganisms metabolize organic matter, and the chemical energy is then converted into usable electrical energy. The microorganisms inside the microbial power cell can metabolize organic waste and agricultural by-products such as manure, corn stover, or straw. This type of power cell is therefore inexpensive because it relies on mass-produced waste materials, which are not usually utilized.

These cells consist of an outer membrane that contains isolated bacteria inside, and an inner membrane that separates an aqueous solution from a nutrient solution.

The idea of generating electricity from microbes was first invented by Professor of Botany at Durham University MC Potter in 1911 when he succeeded in generating electricity from Escherichia coli. Twenty years later, Barnett Cohen created the first semi-microbial fuel cells in 1931, capable of generating a current as small as 2 milliamps.

By 1999, researchers in South Korea had developed microbial fuel cells that boosted their commercial viability by eliminating costly intermediate chemicals needed for electron transfer.

How do microbial fuel cells work?

Like other fuel cells, an electric fuel cell consists primarily of a positive anode and cathode, each housed in a chamber, separated by a proton exchange membrane, a small filter that allows only very small positive charged particles to pass through.

The negative electrode is the electrode where microorganisms reside, it is immersed in organic matter, and there is no oxygen in it. Bio-oxidation takes place in which electrons are removed from organic matter by microbes that can transfer electrons out of their cells.

Negative electrons from oxidation reactions in the cathode chamber are delivered through the wire that connects the positive and negative electrodes to the anode. The hydrogen ions produced by the anode move toward the negative electrode because it is surrounded by oxidizing substances like air, water, or potassium ferricyanide. electrode, thus completing the electrical circuit.

An oxidizer, or oxygen, present in the anode combines with hydrogen and electrons from the cathode to produce pure water, completing the circuit. The cord can be replaced by a light bulb, for example, or any other electrical device to meet your energy needs.

Microbial fuel cell applications

Microbial fuel cells cannot power any electrical device like other energy sources, they need a continuous stream of nutrients, but they can be used in several areas:

  •  Generating energy through biodegradable waste and treating carbon-rich wastewater.
  • Assistance in wastewater treatment and biological treatment.
  • Monitor the amount of biodegradable materials remaining in wastewater streams.
  • Remotely operating biosensors, which are powered by self-power.
  • Converting carbon-rich wastewater streams into methane with high quality.
  • Remotely operating bacteria-powered vehicles in space.

The electric currents generated by microbial fuel cells are still relatively low because the electrons released during cellular respiration do not travel well from the bacteria to the anode.